Search

A new abietane diterpenoid glycoside, ajugaside B (

A phytochemical study was carried out on

The chemical composition of essential oil obtained from the aerial parts of Ajuga comata Stapf. was analyzed by GC and GC/MS. Thirty-seven components were identified in the oil. (E)-β-caryophyllene (30.9%), caryophyllene oxide (24.9%), (E)-β-farnesene (12.6%), β-eudesmol (3.2%), δ-cadinene (3.1%) and germacrene D (3.0%) were the main compounds in the EOs. The chemical composition of A. comata Stapf. from the Southern Zagros of Iran is reported for the first time.

The chemical composition of the essential oil from the aerial parts of three Lamiaceae species from Uzbekistan was investigated by GC-MS analysis. β-Linalool (26.6%), α-terpineol (10.0%), coumarin (8.9%) and 4,5,7,7α-tetrahydro-4,4,7α-trimethyl-2(6H)-benzofuranone (5.4%) resulted as the main components of Ajuga turkestanica essential oil, while camphene (17.1%), 1,8-cineole (15.9%), β-cymene (7.9%) and limonene (7.4%) in Phlomis regelii. The essential oil of Thymus seravschanicus was dominated by thymol (37.5%), phellandral (26.0%), τ-terpinene (6.6%) and β-cymene (5.2%). The essential oils had considerable antimicrobial activity against different bacterial strains and fungi. Among the tested samples of essential oils, P. regelii essential oil has the significant antioxidant activity with IC50 value of 117.8 ± 8.02 μg/mL.

A selection of steroids, glycerides, clerodane diterpenoids, and a beta-hydroxy fatty acid methyl ester, all previously isolated from Ajuga pseudoiva leaves, were tested for their antibacterial activity toward three Gram- rods and one Gram+ coccus using the dilution method; MIC values were determined. The results suggested some importance for a free beta-hydroxy group in the fatty acid ester and also in the glycerides and clerodane derivatives; the absolute configurations of the latter, notably at C2, had little influence on activity.

A new phthalic acid ester 1,2-benzenedicarboxylic acid bis(2S-methyl heptyl) ester (1) was isolated from the hexane extract of the whole plant of Ajuga bracteosa. In addition, chloroform and methanol extracts yielded neo-clerodane diterpene ajugarin-I and two iridoid glycosides, reptoside and 8-O-acetyl harpagide. The structures of all the compounds were confirmed by extensive spectroscopic analysis. From the two oily fractions nine and six volatile constituents respectively were identified by GCMS. Linalyl acetate was found to be common in both the oil fractions. This plant is a new source of linalyl acetate, a valuable perfumery compound.

An iridoid glucoside reptoside ( 1) has been isolated as a DNA damaging active agent by bioassay-guided fractionation of the methanol extract of Ajuga postii. Furthermore, from the acetone extract of A. postii two known triterpenic compounds ursolic acid, alpha-amyrin and two steroidal compounds ( 24S)-24-ethylcholesta-5,25-dien-3 beta-ol and beta-sitosterol were isolated. Their structures were elucidated based on 1D and 2D NMR techniques and mass data.